Tolling coming this fall to new SR 509 Expressway near Kent

Portion of new expressway off of Interstate 5 now open

By Steve Hunter • August 16, 2025 5:16 am

The tolls are coming! The tolls are coming!

Drivers will get a free ride initially with the new portion of the State Route 509 Expressway open in SeaTac, just north of Kent off of Interstate 5, but tolling will start in the fall.

The new exit off I-5 northbound is near South 216th Street and takes drivers west over to 24th Avenue South in SeaTac, just east of Pacific Highway South. Drivers headed east on the new expressway enter I-5 southbound near South 216th Street.

The toll road will be free to use through the summer, according to a Washington State Department of Transportation (WSDOT) blog on Aug. 4.

The SR 509 Completion Project builds 3 miles of new tolled highway between I-5 and South 188th Street near the south end of Sea-Tac Airport, according to WSDOT. Though only the first mile of the road, between I-5 and 24th Avenue South is open now, the rest of the project is on track to be completed in 2028.

Tolling begins this fall on the SR 509 Expressway, although WSDOT has not released an exact date.

Tolls will be charged on both directions of the new road, near the I-5 on- and off-ramps. The tolls will vary by time of day and range between $1.20 and $2.40 for drivers of two-axle vehicles, like a sedan or SUV, with a Good To Go! pass, according to WSDOT. Drivers of vehicles such as semi-trucks, vehicles towing a trailer and large buses will pay more based on the vehicle’s number of axles.

“There won’t be any toll booths, you just drive through without stopping and we’ll charge a toll to your account or mail a bill to the vehicle’s registered owner after the trip,” according to WSDOT. “Only the new portion of SR 509 will be tolled, all the roads you’re already familiar with will continue to be open and free to use. There are also no HOV lanes on the expressway, so there will be no options for toll-free carpooling.”

The state Legislature approved funding for the Puget Sound Gateway Program in 2015. The program includes the SR 509 Completion Project in King County and the SR 167 Completion Project in Pierce County, which completes two major unfinished highways in the Puget Sound region.

State leaders began looking at tolling to help pay for the new roads more than a decade ago.

The estimated cost for the two projects is about $2.8 billion, with $2 billion coming from the state, mainly from a portion of the state gas tax, according to the WSDOT website. Tolling will contribute about $180 million. Local contributions from impacted jurisdictions brings in about $130 million. Another $74 million is from federal grants.